Lubricant containing di-iso-butyl phenol



Patented Apr. 2, 1940 UNITED STATES LUBRICANT CONTAINING DI-ISO-BUTYLPHENOL Troy Lee Cantrell, Lansdowne, Pa., assignor to Gulf OilCorporation, Pittsburgh, Pa", a corporation of Pennsylvania No Drawing.

Application September 2, 1936,

Serial No. 99,157

4 Claims.

This invention relates to improved mineral oils and more particularly tomineral oils having an anti-sludging agent incorporated therein toobtain marked resistance of the oil to sludging 5 and discoloration whenthe oil is subjected to oxidizing conditions, said improvement agentcomprising di-iso-butyl phenol, and to methods of making such improvedlubricants, all as more fully hereinafter set forth and as claimed.

It is a well established fact in the petroleum art that oils containingsulfur, nitrogen, and related components show a tendency to sludge anddiscolor when subjected to oxidizing conditions. This is true whetherthe said constituents occur naturally in the mineral lubricating oil, asis the case especially with some naphthenic base lubricents, or whethersulfur, nitrogen, chlorin, phosphorus and/or related compounds areartificially introduced for specific purposes as in the case of 20improved lubricants. It has been observed that improvement agents whichare most effective for mineral lubricating oils and most economicallyemployed to impart desired anti-corrosive and extreme pressureproperties, while having no deleterious efi'ect on the other originalproperties of the lubricating oil base, have been found to increase thetendency of the oil to sludge and discolor upon oxldation under extremeconditions of use. An object of my invention is to provide animprovement agent which will in no way alter the desirable properties ofthe original lubricant, but which, when incorporated with a minerallubricating oil, will inhibit the tendencies of the improved oils tosludge and discolor when the lubricant issubjected to oxidizingconditions at high temperature and extreme pressure for a relativelylong period of time. I have found, and herein disclose and claim, ahighly eifective improvement agent, which, when added to a mineral oil,as for example to improved mineral lubricating 011 containing one of theaforesaid improvement agents, will overcome the aforementioneddifiiculties without adversely affecting the desirable properties of theoil.

The improvement agent of my invention is diiso-butyl phenol. It is achemical compound, having the following structural formula:

of the various isomers either singly or in mixture with one another.

Di-iso-butyl phenol is a white crystalline solid, soluble in mineraloils to the extent oi 0.50% by as weight.

My invention is directed to the use of this compound as ananti-sl'udging agent for hydrocarbon oils, particularly for minerallubricating oils. Mineral oils that develop a tendency to sludge and todiscolor when used under oxidizing con- 5 ditions such as occur at hightemperature for long periods of time, when blended with a very smallamount of di-iso-butyl phenol, show marked resistance to these undesiredphenomena, with no deleterious effect upon the desirable properties ofthe oil. Resistance to color change is particularly marked with oilscontaining as little as 0.10 per cent by weight of di-iso-butyl phenol.

The improvement agency of my invention is readily incorporated in amineral oil. The ordinary equipment and usual procedure employed inblending oils will sufifice for incorporating this compound in any oil.Since heat lowers the viscosity of oils, solution of the compound in theselected 011 is facilitated by heating the oil somewhat. I have foundthat heating the oil to 160 to 180 F., and adding thereto the requiredamount of di-iso-butyl phenol while blowing the mixture with a currentof air for one hour is an advantageous procedure for blending theimprovement agent with a selected oil. The improvement agent may beadded all at one time and the mixture subsequently well agitated. Therequired proportion of di-iso-butyl phenol to lubricating oil isvariable, being dependent upon the character of the oil to which it isadded. The less stable mineral lubricating oils require higherpercentages of di-iso-butyl phenol, the proportions ordinarily beingfrom 0.02 per cent to 0.25 per cent by weight of the improvement agentto inhibit the ordinary tendencies to sludge and to discolor, althoughsomewhat more is sometimes necessary.

The following examples are presented to illustrate the properties ofimproved lubricants prepared in accordance with my invention, comprisinga major proportion of mineral lubricating oil and a minor proportion ofdi-iso-butyl phenol as the anti-sludging agent.

The data recorded below werefobtained to determine the properties ofimproved lubricants comprising a major proportion of mineral lubricatingoil, or a mineral lubricant base in which some anti-corrosive agent hasbeen incorporated and a minor proportion of di-iso-butyl phenol toinhibitsludginganddiscoloration. Threesamples of mineral lubricating oilwere subjected to oxidation in the following corrosion test: A newcadmium-silver bearing shell was immersed in 300 cc. of minerallubricating oil for 48 hours and throughout that period the oil wasmaintained at 347 F. (175 C.) and 2000 cc. of air per hour was bubbledthrough the heated oil and against the surface of the bearing. The firstsample of oil, Number 1, was a highly refined parafilnic 60 basePennsylvania motor oil. The second sample of oil, sample Number 2, wassubjected to the same corrosion test. This sample Number 2 was animproved lubricating oil consisting of principally the same oil assample Number 1, together with a small percentage of one improvementagent which has been found exceeding efllcacious in inhibiting corrosionand in enhancing the lubricating value of the oil under extreme pressureconditions but which improvement agent has one deficiency in that whenit is subjected to oxidizing conditions at high temperature and underextreme pressure for a long period of time it has the effect ofincreasing the rate of generation of sludge in the oil. Increasedsludging with this particular anti-corrosion agent was also accompaniedby discoloration of the oil, and these facts have been noted withrespect to a number of other highly eificacious improvement agents forlubricating oils. A third sample, sample Number 3, consisting only ofmineral lubricating oil and di-iso-butyl phenols was subjected to thesame corrosion test to determine if di-iso-butyl phenol, whenincorporated in a mineral oil, had any deleterious effects on theoriginal oil. A fourth sample, sample Number 4, was an improvedlubricant consisting of a portion of the same stock of oil as sample 1,0.25 per cent of the anticorrosion agent used in sample Number 2, and0.10 per centof di-iso-butyl phenol. The following results are tabulatedfor this study:

Composition Samplel Sample2 Samp1e3 Samplei Pa. motor oil SAE lg deercen $121101"? 100 09.00 99.75 90.05 Anti-corrosion agen perce ntwleightfihfllu 0. 0. 25 0. 25 Di-isou p eno percent v i leight 0 o. 100.00 0.10 Cd-Aghtbearing shell,

rams: lgior e lz e t 27. 7875 27. 6667 27. 4835 27. 3975 At end of test27.3670 27.5263 27.4830 27.3970 Total loss 0. 4205 0. 1404 .0005 0. 0005Appearance alter Severely Etched Good Good test. corroded Lulbrcant,site: su e, rcen nap tha-i liso materiaL 0. l0 0. 0. 26 0. 05

Samples 1, 2, 3, and 4'were all prepared with a highly refined Penna.SAE grade mineral lubricating oil. Samples 5, 6, and 7 were preparedwith a solvent refined Mid-Continent oil of SAE grade and these samplescompare, respectively, with samples 1, 3, and 4.

An inspection of physical properties was made before the oxidation teston each .of the samples shown above to demonstrate that the addition ofthese improvement agents to a mineral lubricating oil does not adverselyaffect the physical properties of the oils to which they are sampleswere as follows:

Composition Sample 1 Sample 2 Sample 3 Sample 4 Ps. motor oil SAE 10grade; percent weight. 1(1) 00. 75 00.00 00.66 Anti-corrosive agent,

percent ht 0 0. 0 0. 05 Di-iso-butylp one], percent weigh 0 0 0. l0 0.10

Inspection Gravity, API 33. 1 32. 7 38. 0 32. 6 Viscosity SUV:

100' l m0 180 m 180 130 F N W 8 08 210 F 40. 2 46. 0 40. 0 no 415 400400 0 0 1. 25 I. 25 02 02 02 Sltisfac- Satisfacwry tory CompositionSample 5 Sample 6 Sample 7 Mid-Continent motor oil SAE ZOgrade; percentweight 100 09. 75 99. 65 Anti-corrosion agent,

rcent weight 0 0. 25 0. 25 D -iso-butyl phenol,

percent weight l. 0 0 0. 10

Inspection Gravity. API 28.1 %.0 E. l Viscosity, SUV:

100 F 206 290 306 21 51 51. 6 51 Flash. 0 0.: "F 415 420 425 Fire, 0 CT. 480 485 490 Pour, F 0 +5 0 Color, NPA 3. 50 3. 75 3. 75 Carbonresidue. l2 10 .07 Copper strip test Satisfactory SatisfactorySatisfactory Di-iso-butyl phenol is not highly effective as ananti-corrosion agent for preventing the destructive eilfect oflubricating oils on the newer bearing metals, but is highly eflective asan antisludging agent for oils that have a tendency to sludge. Almostall corrosion inhibitors are compounds containing sulfur, nitrogen,phosphorus, or chlorin, some of which compounds frequently tend toproduce sludge despite their marked and measurable influence upon theanticorrosive and extreme pressure properties of mineral lubricatingoils. Few organic compounds retain their original properties for anylength of time when maintained under servere conditions of temperatureand aeration and the newer laboratory tests advocated for evaluating thebehavior of bearing alloys in aerated oils at elevated temperatures andunder high pressure provide evidence of the fact that improvedlubricants sometimes develop more sludge than is considered permissible.Development of excessive sludge occurs particularly when improvedlubricants are subjected to some of the various test procedurescurrently proposed for evaluating corrosion inhibitors for extremepressure lubricants. It is especially diflicult to produce an improvedlubricant which will satisfy all of the various corrosion tests incurrent use and still have the desired low sludging tendency.Di-isobutyl phenol, as set forth herein, is peculiarly adapted for useas an auxiliary improvement agent with those improved lubricating oilswhich show special tendency to sludge and to discolor during use, anddi-iso-butyl phenol is likewise highly eillcacious in reducing thesludging tendency of those mineral lubricating oils which do not containother improvement agents, as well sludge.

structive action on the bearing surfaces. Due to the presence of theimprovement agents employed, those new lubricants withstand drasticservice conditions for relatively long periods, before they fail. I havefound that when they fail, the primary cause is due to the formation ofThus with such improvement agents present, sludging is encountered withlubricating bases which without said improvement agents would fail fromother causes before sludging occurs; this sludging being encounteredbecause of the longer period of usefulness of such improved lubricants.By the present invention, those lubricants may be further improved andtheir utility extended for a much longer time. In

applications Serial Nos. 98,826; 98,827; 99,156; 83,761; 83,760, nowissued, respectively, as Patents Nos. 2,134,432, and 2,134,433 ofOctober 25, 1938; 2,109,463 of March 1, 1938 and 2,145,971 and2,145,970of February 7, 1939, and 84,974 (filed by myself and one JamesO. Turner) and Serial No. 84,386 (filed by myself and one Herschel G.Smith) such improved lubricants are disclosed and claimed and I havefound that the improved lubricants there described may be furtherimproved by the addition of di-iso-butyl phenol. In those lubricants,various organic thio-ethers, organic poly-sulfides, alkoxy-hydroxybenzenes and sulfo-chlorinated monoesters of fatty acids are employed asthe said improvement agents. Thus mineral lubricating oils containingany one of the following compounds as the improvement agent may beimproved by adding the amounts of di-iso-butyl penhol given ante:

Alkyl thio-ethers of ortho-nitro benzene.

Alkyl thio-ethers of ortho-amino-benzene.

Alkyi thio-ethers of, alpha-anthraquinone.

3-alkoxy-4 hydroxy benzaldehydes.

Iso-eugenol.

Diamyl poly-sulfides.-

Sulfo-chlorinated sperm oil and like monoesters of fatty acids of theoleic series.

For instance, mineral lubricating oils containing small amounts, say afraction of a per cent of alkyl thio-ethers, such as amyl thio-ethers ofortho-nitro-benzene, of ortho-amino-benzene or of thealpha-anthra-quinone, may be improved by the addition of from 0.02 to0.25 per cent of di-iso-butyl phenol to obtain lubricating com-.positions improved as to sludging. Mineral compositions containingsimilar amounts of vanillin or iso-eugenol may be likewise improved asto their sludging characteristics. The addition of a similar amount ofdi-iso-butyl phenol, to improved lubricants containingdiamyl-poly-sulflde, such as triand tetra-sulfides, or sulfo-chlorinatedsperm oil, effects like improvements in their sludging characteristics.

What I claim is:

1. As an improved lubricant, the lubricating composition comprising amajor amount of mlneral lubricating oil, a fraction of a per cent of analkyl thioether and from 0.02 to 0.25 per cent of a di-iso-butyl phenol,said composition having pressure and sludging characteristics comprisinga mineral oil having added thereto a small amount of an alkyl thioetherof ortho-nitrobenzene and 0.01 and 0.5 per cent of a di-iso- 'IROY LEECANTREIL.

butyl phenol.

